The medical device industry produces a wide variety of electronic and mechanical devices suitable for use outside and inside the body for treating patient disease conditions. Devices used outside the body are termed external while devices used inside the body are termed implantable medical devices and include devices such as neurostimulators, drug delivery devices, pacemakers, defibrillators, and cochlear implants. Clinicians use implantable medical devices alone or in combination with therapeutic substance therapies and surgery to treat patient medical conditions. For some medical conditions, implantable medical devices provide the best, and sometimes the only, therapy to restore an individual to a more healthful condition and a fuller life.
Implantable medical devices can be used to treat any number of conditions such as pain, cancer, incontinence, movement disorders such as epilepsy, spasticity, and Parkinson's disease, and sleep apnea. Additionally, use of implantable medical devices appears promising to treat a variety of physiological, psychological, and emotional conditions.
Implantable medical devices have important advantages over other forms of therapeutic substance administration. For example, oral administration is often not workable because the systemic dose of the substance needed to achieve the therapeutic dose at the target sight may be too large for the patient to tolerate without very adverse side effects. Also, some substances simply will not be absorbed in the gut adequately for a therapeutic dose to reach the target sight. Moreover, substances that are not lipid soluble may not cross the blood-brain barrier adequately if needed in the brain. In addition, infusion of substances from outside the body requires a transcutaneous catheter, which results in other risks such as infection or catheter dislodgement. Further, implantable medical devices avoid the problem of patient noncompliance, namely the patient failing to take the prescribed drug or therapy as instructed.
For example, one type of medical device is an Implantable Neuro Stimulator (INS). The INS is implanted at a predetermined location in the patient's body. The INS generates and delivers electrical stimulation signals at neurostimulation sites or areas to influence desired neural tissue, tissue areas, nervous system and organs to treat the ailment of concern. The stimulation sites can also include the spinal cord, brain, body muscles, peripheral nerves or any other site selected by a physician. For example, in the case of pain, electrical impulses may be directed to cover the specific sites where the patient is feeling pain. Neurostimulation can give patients effective pain relief and can reduce or eliminate the need for repeat surgeries and the need for pain medications.
Implantable medical devices are often used in conjunction with various computer and telecommunication systems and components. Information obtained by the implantable medical device may be stored and subsequently transmitted to a physician or patient caregiver or a database on demand or automatically. Many ways of using the information are known including decision making to provide optimum medical care to the person with the medical condition.
For example, an external device such as a physician programmer can be used to allow a physician to communicate with the implanted medical device. The physician programmer allows the physician to create and store stimulation therapy programs for the patient to be delivered by the implanted medical device. The physician programmers also serve to recharge a rechargeable power source in the implanted medical device.
Typically, the physician programmer communicates bi-directionally with the implanted medical device via RF telemetry signals. The bi-directional communication between the medical device and the physician or patient programmer is typically accomplished via a telemetry module. The physician programmer, the patient programmer and the medical device each have respective telemetry modules that allow for bi-directional communication between the medical device and the programmers. The bi-directional telemetry communication, between the medical device and the physician or patient programmers is typically conduced at frequencies in a range from about 150 KHz to 200 KHz using existing telemetry protocols. A telemetry protocol is generally an agreed-upon format for transmitting data between two devices. The protocol can be implemented in hardware and/or software. The protocol determines, for example, the type of error checking to be used, the data compression method, if any, how the sending device will indicate that it has finished sending a message, how the receiving device will indicate that it has received a message, etc. There are a variety of protocols, each having particular advantages and disadvantages; for example, some are simpler than others, some are more reliable, and some are faster. Ultimately, the external device must support the right protocol(s) in order to communicate with implanted device.
Commercially available systems, however, are limiting in that the physician programmer is configured to provide telemetric communication using one or more pre-specified communication protocols. Accordingly, the physician programmer is typically only capable of communicating with those implanted medical devices that utilize those protocols. For each of the varying types of implanted devices available, the physician would need to have separate physician programmers that were compatible with each of the devices. Similarly, if the patient had more than one implanted device, the physician would likely need more than one physician programmer, one for each implanted device.
It is therefore desirable to provide a physician programmer that may be operated using any number of protocol schemes so that it may communicate with any number of implanted devices.